1. Field of the Invention
This invention relates to an expansion joint containing an intersection of two or more sections. More particularly, this invention relates to an expansion joint and a seal for an expansion joint containing an intersection.
2. Description of the Prior Art
Expansion joints are known and one type of expansion joint is described in Braun U.S. Pat. No. 4,774,795.
Designs of structures using expansion joints sometimes require the expansion joints to contain an intersection. Typically, the intersection is an L-shaped intersection, a T-shaped or a Y-shaped intersection, or a four way intersection that has four sections where the angles between each section are approximately 90.degree.. Expansion joints containing intersections have not worked particularly well as each area of the expansion joint is subjected to different forces when the structure in which the joint is located expands or contracts. The combination of the forces on the expansion joint during an expansion phase sometimes causes the seal of the joint to rise above the road surface where the expansion joint is installed. On other occasions, the seal twists uncontrollably and the twisting unreasonably limits the degree of expansion that the seal can undergo without tearing. On still other occasions, the seal is pulled out of supports that are designed to hold the edges of the seal in place. Mitring is sometimes used to construct a seal containing an intersection. When mitring is used, the seal is weak along a line where the mitring has occurred.
The Moerk, Jr. U.S. Pat. No. 4,033,702 describes a joint assembly for sealing the gap between roadway slabs at curb and sidewalk portions where the assembly has a flexible sealing flap member. The Girot U.S. Pat. No. 3,118,523 describes a connecting element for expansion joints to be used at an intersection. Sometimes, seals of expansion joints containing intersections cannot be easily cleaned and debris builds up in the seal, causing the seal to fail prematurely. During a contraction phase, the joint closes on the seal, which is forced against the debris, sometimes tearing the seal or transmitting damaging stresses to the structure. With some previous expansion joints containing intersections, the seal can only withstand a small range of expansion or contraction.